BSOD after Win7 SP1 update?

[toddk63]

I have successfully installed WintoUSB / Win 7 Ultimate on a WD Passport 1TB USB drive running off of a Dell Laptop (Latitude e6120 ?).  The laptop only has USB 2, no USB 3.0.  After many updates (no problems) and then the SP1 big update I get BSOD "Stop: 0x00000050" after the Win7 splash screen. There is no further info as to which file or driver is causing this. So then I found the Win 7 ISO with SP1 on it already.  This seemed to work as well, then after a couple of updates...BSOD!  It will boot in Safe Mode. There is no minidump file generated. I need to check if minidump is enabled. I have uninstalled the last 4 Windows updates, but one of them, KB2515325, keeps re-installing itself on reboot even though I have selected "No automatic install..."  This is suspicious.

I've seen lots of threads about BSOD from trying to boot WintoUSB/Win7 from USB 3.0 but nothing like I have described.

Any ideas?

Thanks,

Todd K.